The maze, symbol of secrets and games of mankind's own making, triggered the inspiration for English National Opera's new The Marriage of Figaro, directed by Fiona Shaw and conducted by Paul Daniel. A network of grey-white walls spins on a revolve, swirling us through public, private and domestic quarters in Count Almaviva's household, as if we ourselves are characters, hastening blindly towards elusive centre or thankful exit.

This was the dominant theme in a production full of thought and care but which, in all its exhausting frenzy, has not yet settled into a coherent entity. Shaw's stagings of Henze's Elegy for Young Lovers and Vaughan Williams's Riders to the Sea are among ENO's recent best. In Figaro she leaves her intelligent fingerprint on each teasing gesture or exploration – and often amplification – of Da Ponte's libretto, often where none is needed.

Shadow play, video and a bustle of between-scenes playfulness ensure restless activity. I blame myself that I am hooked on some arcane notion that the overture, a gem of musical economy, should be a warm-up exercise to sharpen our ears for the ingenuities of Mozart's score before it unfolds: a brief, unadulterated contemplation of notes, rhythms, harmonies lasting around four minutes.

When eyes, too, are engaged that opportunity is lost, sacrificed on the altar of production values. Shaw is only following current practice here, in providing a scene-setting tableau vivant. But already our minds are in overdrive, puzzling over the concept, wondering who's who or why, in a mainly frock-coated world, that vacuum cleaner is standing centre stage. Daniel, who also provided a beautifully discreet fortepiano continuo, urged clean, vivid playing from the orchestra, though the ensembles still need more time to breathe. The cast, too, is alive with promise, led by Iain Paterson who, despite looking like a vintage fireman, is an interesting Figaro, with Devon Guthrie his vivacious, independent-minded Susanna. Mary Bevan shone in the minnow-sized role of Barbarina, nearly upstaging Kathryn Rudge's alert Cherubino. Elizabeth Llewellyn's Countess was an admirable late replacement for an indisposed Kate Valentine. But this unfortunate blow inevitably disturbed the dramatic balance Shaw had worked hard to achieve.

Her wisdom in spoken theatre makes you willing to countenance her ideas, even if they baffle: the Count (Roland Wood) variously appears in boxer shorts, clutching a doll and dragging freshly slaughtered game into his wife's bedroom; the servant Figaro shuns social nicety and sits down carelessly in that same room, leaving the Countess herself on her feet; the omniscient gossip, Don Basilio, is blind for no obvious reason beyond making him, inexplicably, a figure of pathos. In case you cannot imagine what goes on below stairs, Shaw fills in every dark detail from urination to, very nearly, buggeration.

Each of the four acts, as specified by Da Ponte, has a sense of place, underlined by the character of the music, notably the unexpected F minor opening to the garden scene. Peter McKintosh's minimalist designs, lit by Jean Kalman, uproot and blur that clarity. Yes, props such as kitchen chairs or hunting trophies give a clue, but in this endlessly revolving world the real turning points have to fight for recognition. For now, my usually reliable jury, resting after this frenetic battering, is still out. Anyone planning to go, and I hope to return to hear Valentine, would do well to purchase the latest excellent ENO Overture Opera Guide on Figaro, just published.

The Scottish season began last week with a heartening sense of loyal audiences and orchestras renewing acquaintance. In Glasgow, a packed City Halls leapt to its feet as the final note of James MacMillan's fiercely human, often cataclysmic St John Passion sounded, blisteringly performed by the BBC Scottish Symphony Orchestra, BBC Singers, London Symphony Chorus and baritone Mark Stone as Christus.

MacMillan's musical gestures, steeped in liturgy and with opulent harmonies, also embrace non-western tonalities and exultant dissonance. His popularity, or perhaps his open relationship with his Catholic faith, has laid him open to critical carping. No one present could deny the work's impact. The rose-window comparison, in which the saturated colours of stained glass are held within a lattice of stone, or in MacMillan's case two sections subdivided into chapters of Gospel narrative, might seem hackneyed. Yet it hints at the visionary ambition of this choral epic, conducted by Donald Runnicles with masterly ease.

The next night in Edinburgh, Stéphane Denève launched his final season as music director of the Royal Scottish National Orchestra with a quirky "Auld Alliance" theme. At the start, three kilted pipers from the National Youth Pipe Band of Scotland offered a prelude: "Meggernie Castle". This traditional melody was used in Debussy's Marche écossaise sur un thème populaire which followed without a break. The leap from poignant bagpipes to luscious orchestral textures set the mood. The Scottish-born star violinist Nicola Benedetti, sinuous and sinewy, succeeded in making Bruch's tedious Scottish Fantasy sound interesting – no mean achievement.

The evening featured a world-premiere commission from the French composer Fabien Waksman (b 1980). Skilful and sonorous though his music is, Le parfum d'Aphrodite remains an old-fashioned kind of scent. Waksman describes the piece as "a hymn to beauty and femininity", a sentiment uttered apparently without irony. A simple, rocking figure builds to a thundering climax, representing the goddess of love's watery birth, ebbing away to close as it opened. Waksman wrote it as a companion to Debussy's La mer, also performed in a surging account and sounding far more radical despite being written at least 100 years earlier.

Heading south, I diverted to Liverpool to hear Mahler's Symphony No 8. Usually I'd divert in order not to hear it, but the Royal Liverpool Philharmonic Orchestra, playing this work in the penultimate concert of their Mahler cycle, are on a high and demand attention. Its chief conductor, the 35-year old Russian Vasily Petrenko, has earned worldwide recognition. A major new record deal is rumoured, surely guaranteed following this week's Gramophone award for best orchestral recording (for Shostakovich's 10th).

Their "Symphony of a Thousand" was a knockout. Given in Liverpool's lofty Anglican Cathedral, symphony and venue were perfectly matched. The first red sandstone blocks of this edifice were laid around the time Mahler completed his score in 1910. 500 performers, with top soloists, several choirs and offstage brass in a high gallery, gathered beneath the soaring transept and gave their all.

It took a while to steer an aural path through the slowly echoing acoustic, but in this symphony, communal experience counts for more than subtlety. Petrenko looked shattered at the end, overwhelmed by the reception. He exhorted his musicians to play the finale again, converting us all to a spontaneous belief in Mahler and the RLPO in general, and Petrenko in particular.

Back in London I caught the end of the Southbank's Pierre Boulez weekend: his ever-evolving classic Pli selon pli, sexily sung by Barbara Hannigan and conducted by the composer. For 50 years, at times in UK residence, at others a mere waft of Gallic smoke tickling our noses from afar, Boulez has acted as cultural scourge and redefined concert life.

Born in 1925, he spans the French musical century between Debussy and, since his name was new this week, Fabien Waksman. There are those who dismiss Boulez as a pretentious anachronism. Who will date sooner: the radical octogenarian or the young conservative contender? No contest.